Triangular Arrangements In Germanium Phases Probed By Xas

We present results of the analysis of K-edge X-ray-absorption spectra of crystalline, amorphous, and supercooled Ge. The EXAFS spectra are analyzed in k space by comparison with theoretical signals calculated including the total multiple-scattering (MS) contributions related to pairs and triplets of Ge atoms. MS signals of triangles are unambiguously identified in the various systems investigated